Hannover 2010 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 21: Poster I

Q 21.19: Poster

Dienstag, 9. März 2010, 16:00–19:00, Lichthof

Optical interface created by laser-cooled atoms trapped in the evanescent field surrounding an optical nanofiber — •Rudolf Mitsch, Melanie Müller, Daniel Reitz, Eugen Vetsch, Samuel T. Dawkins, and Arno Rauschenbeutel — QUANTUM, Institut für Physik, Johannes Gutenberg-Universität Mainz, 55099 Mainz

We optically trap neutral cesium atoms close to the surface of an optical nanofiber with a diameter of 500 nm. The atoms are cooled with a standard magneto-optical-trap and loaded into a 1d optical lattice formed 200 nm above the fiber surface by a two-color evanescent field surrounding the fiber. The red- and blue-detuned trap lasers are far detuned and have a total power of about 40 mW, resulting in a trap depth of a few hundred µK. In order to detect the atoms in the trap, we measure the transmission of a weak resonant probe beam, launched through the fiber. At resonance, each atom absorbs about one percent of the probe via evanescent field coupling, yielding a high optical density of up to 18 for about 2000 trapped atoms. In the dispersive regime, we measure the interaction-induced phase shift experienced by the probe via the effect on its polarization state. Finally, using an optical conveyor belt technique, we demonstrate transport of the atoms along the fiber. Our work opens the route towards the realization of hybrid quantum systems that combine atoms with, e.g., solid state quantum devices and towards non-linear optics applications based on electromagnetically induced transparency.

Financial support by the ESF (EURYI Award) and the Volkswagen Foundation (Lichtenberg Professorship) is gratefully acknowledged.